The attention of the present paper is focused on the investigation of thermoplastic composites involving a polylactic acid (PLA) matrix reinforced with woven jute fibres. Both matrix and fibres are natural renewable materials and are in line with the growing environmental awareness, which is driving attention towards the development of more ecological and friendly materials. However, PLA composites have till now received scarce attention and their characteristics are still not completely understood. Conversely, understanding the material characteristics and performance is important in view of its proper application use. In light of this last consideration, laminates obtained by the conventional film-stacking process were characterized in terms of flexural and Charpy impact behaviour and their failure evolution was analysed by infrared thermography. Results from mechanical tests showed an increase of both flexural and impact strength of composite systems with respect to the neat matrix. Infrared thermography, thanks to its non-contact character, can be used to monitor the entire existence of a product, from its manufacturing process to completion as well as in-service life. In the present work an infrared imaging device was used with a twofold function: oas non-destructive testing system (lock-in thermography) to discover either manufacturing imperfections as well any damage occurred under load (bending, or impact); oas monitoring instrument to visualize thermo-elastic/plastic effects developing under load, like cyclic bending tests and impact tests, which can be exploited to assess the material performance. The obtained results while showing the advantages of using an infrared imaging device to monitor either bending, or impact, tests, also supply information useful for the material characterization. In particular, owing to bending tests, data reported in terms of average ?TA values fall over a line intercepting the x axis at x/L = 1 in agreement with the bending moment diagram. This, in consideration of the relationship between stress and temperature variations, help assessing the material performance in a fast and non-destructive way. With regard to impact tests, the thermal signatures visualized over the side opposite to impact supply useful information for the material impact performance specifically for identifying initiation and propagation of the impact damage with varying the impact energy.
PLA/Jute composite laminates: mechanical tests and infrared thermography
Pietro RUSSO;
2016
Abstract
The attention of the present paper is focused on the investigation of thermoplastic composites involving a polylactic acid (PLA) matrix reinforced with woven jute fibres. Both matrix and fibres are natural renewable materials and are in line with the growing environmental awareness, which is driving attention towards the development of more ecological and friendly materials. However, PLA composites have till now received scarce attention and their characteristics are still not completely understood. Conversely, understanding the material characteristics and performance is important in view of its proper application use. In light of this last consideration, laminates obtained by the conventional film-stacking process were characterized in terms of flexural and Charpy impact behaviour and their failure evolution was analysed by infrared thermography. Results from mechanical tests showed an increase of both flexural and impact strength of composite systems with respect to the neat matrix. Infrared thermography, thanks to its non-contact character, can be used to monitor the entire existence of a product, from its manufacturing process to completion as well as in-service life. In the present work an infrared imaging device was used with a twofold function: oas non-destructive testing system (lock-in thermography) to discover either manufacturing imperfections as well any damage occurred under load (bending, or impact); oas monitoring instrument to visualize thermo-elastic/plastic effects developing under load, like cyclic bending tests and impact tests, which can be exploited to assess the material performance. The obtained results while showing the advantages of using an infrared imaging device to monitor either bending, or impact, tests, also supply information useful for the material characterization. In particular, owing to bending tests, data reported in terms of average ?TA values fall over a line intercepting the x axis at x/L = 1 in agreement with the bending moment diagram. This, in consideration of the relationship between stress and temperature variations, help assessing the material performance in a fast and non-destructive way. With regard to impact tests, the thermal signatures visualized over the side opposite to impact supply useful information for the material impact performance specifically for identifying initiation and propagation of the impact damage with varying the impact energy.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
